The invention relates to the field of umbrellas and, in particular, to those umbrellas used to cover tables and the like in outdoor settings. Typically such larger umbrellas are used to cover those tables in patios for restaurants and the like. Such umbrellas are typically significantly larger than ordinary hand held umbrellas and greater force is needed to operate them. The actuator sleeve shown and described herein is believed to work well in such applications that call for large umbrella canopies.
Because the distance the spokes that support the ribs of the canopy have been reduced in length and because the spokes connect to the ribs closer to the central "hub" of ribs, the spokes do not have to travel as far in order to open and close the canopy. As the actuator sleeve is in connection with the "hub" this means that the sleeve does not have to travel as far in order to open and close the canopy. There is greater leverage created on the ribs by this decreased distance and this requires greater force to slide the sleeve, however as this work can be done electrically the benefit of the short travel length (of the sleeve) allows the actuating mechanism to be used in such electrical applications without having a long travel length which would require longer movements of the actuator sleeve and would require greater vertical height above the canopy in order to permit this arrangement. The same benefits would apply to manual operation in that less vertical clearance above the canopy would be required.
It is believed that the invention will find its greatest use in opening and closing "patio" type umbrellas which are very popular in restaurants that feature and outdoor settings. Such umbrellas have large canopies that are typically much larger than ordinary hand held umbrellas. Such patio umbrellas of course have larger components: longer length support ribs, larger canopy, larger shafts, etc. Most such canopies use a manual crank in order to open and close the canopy. This requires a greater force for the user to turn the crank and also places additional strain on the cables associated with the mechanism. As the crank turns, the cord or cable is wound upon a drum or similar mechanism, this means that as the cable is wound, the radius of the cable on the drum increases and the drum becomes harder to turn near the end of the cranking. This may result in damage or breaking the cable and also requires greater force for the one using the crank. There is also the possibility of binding the cable when using a crank mechanism.
The inner rod of the invention may be adapted for electronic control, say by a electric motor housed in the umbrella that can operate the inner rod electrically.